Generally described, user computing devices may facilitate the playback or display of items of content, such as audio books, electronic books, songs, videos, television programs, computer and video games, multi-media content, and the like. For example, an electronic book reader computing device (“e-reader”) may display an electronic book on a screen and/or play an audio book through speakers or headphones.
In some instances, multiple items of content may be generated based on a single base content. For example, both an electronic book and an audio book may be generated based on a physical book. Multiple items of content that correspond to the same base content may generally be referred to as “companion” items of content.
In some instances, differences may exist between two companion items of content. Such differences may be due at least in part to differences in format of the items. For example, a textual content may include a table of contents, index or appendices not included within an audio content. In other instances, differences between two companion items of content may indicate that extra substantive material exists within one or both items. For example, an audio book may include a recording of an interview with the author that has not been included within a corresponding electronic book. As a further example, a narrator may choose to omit portions of an electronic book when creating a corresponding audio book (e.g., to reduce the duration of the audio book).